X-ray tip catheter

ABSTRACT

CATHETERS OF THE DISPOSABLE, SEAMLESS, EXTRUDED PLASTIC TYPE ARE MADE WITH DISTAL END PORTIONS THAT ARE X-RAY OPAQUE BY FUSING A PLASTIC ANNULUS CONTAINING X-RAY OPAQUE PIGMENT ONTO THE PREFORMED TUBE. THE CATHETER MAY HAVE ONE OR MORE OF SUCH X-RAY OPAQUE OUTLINED OPENINGS IN THE DISTAL END PORTION AND WHERE A PLURALITY ARE PROVIDED, THEIR SPACING MAY BE PROPORTIONED TO THE SIZE AND TYPE OF THE CATHETER. SUCH X-RAY OUTLINE PORTIONS PERMIT THE POSITION OF THE DISTAL END PORTION OF THE CATHETER WITHIN A PATIENT TO BE DETERMINED BY X-RAY METHODS.

Sept. 20, 1971 D. s. SHERIDAN EFAL 3,605,750

X-RAY TIP CATHETER Filed April 7, 1969 4 Sheets-Sheet 1 Sept. 20, 19710. s. SHERIDAN ETAL 3,605,750

X-RAY TIP CATHETER 4 Sheets-Sheet 2 Filed April 7, 1969 P 1971 o. s.SHERIDAN EIAL 3,605,750

X-RAY TIP CATHETER 4. Sheets-Sheet 3 Filed April 7. 1969 Sept. 20, 1971D. s. SHERIDAN ETAL 3,605,750

X-RAY TIP CATHETER Filed April 7, 1969 4 Sheets-Sheet 4.

United States Eatent O 3,605,750 X-RAY TIP CATHETER Dav d S. Sheridan,Argyle, and Isaac S. Jackson, Greenwich, N.Y., assignors to David S.Sheridan, Argyle,

Filed Apr. 7, 1969, Ser. No. 814,061 Int. Cl. A61m 25/00 US. Cl. 1283489 Claims ABSTRACT OF THE DISCLOSURE BACKGROUND OF THE INVENTION In orderto reduce the possibility of cross-infections and eliminate the expenseof sterilization of reusable type catheters and other medico-surgicaltubes, extensive use is being made of disposable-type catheters designedfor single patient and single use. Such disposable catheters are almostexclusively produced by extrusion of waterproof plastic material whichis non-toxic, non-absorptive and resistant to attack or deterioration byfluids of body tissue into which the catheter or other medico-surgicaltube may be inserted in the course of a surgical or clinical operation(see US. 2,940,126).

In many surgical or clinical procedures, it is important to be able todetermine the location or position of the catheter within the body ofthe patient into which it has been inserted. X-ray observations, e.g.,photographic or fluoroscopic, is a convenient method of making thisposition determination, but the usual plastic material from which thedisposable catheters are formed is not X-ray opaque. Accordingly,several catheters constructions have been devised in order to permit thebody position of catheters to be determined by X-ray observation. Oneknown construction makes the entire tube opaque to both visible lightand X-rays by incorporation of pigment through the tube. Another hasbeen to form on catheters disconnected lines of X-ray opaque material(see US. 2,212,334). A further method has been to extrude plasticmaterial into tubular form with a continuous X-ray opaque stripextending longitudinally along the entire length (see US. 2,857,915).

In many surgical or clinical operations, it is the location of thedistal end portion of the catheter which is most important to know. Therequirement may be for knowledge of the position of the distal tip ofthe catheter, or, for the position of the most proximal eye in thedistal end portion which extends through the side wall of the catheter ashort distance back from the distal tip. Such distal end portion openingdetermination has been accomplished by interrupting a continuous X-rayline formed integrally in a catheter by an opening in the distal endportion of the catheter (see US. 3,190,290).

The variety of medical and surgical procedures for which catheters areemployed require a variety of inlet opening configurations in the distalend portions of catheters, e.g., gastro-intestinal catheters. In somecatheters, a single opening is employed which constitutes the distal tipof the catheter. In others, the catheter distal tip is closed while theinlet opening constitutes an eye through ice the side wall of thecatheter (see US. 2,857,915). In other cases, both a tip opening and oneor more side wall holes may be required (see US. 3,190,290). Theseopenings may be formed by punching, cutting, abrading or the like. Inany event, creation of holes or openings which are smooth and which willnot create irritation or injury to delicate tissues into which thecatheters may be inserted are essential if the catheters are to beacceptable to hospital administrators, surgeons or other partiesinvolved with purchase and use of these products. Various techniques areemployed to create acceptably smooth surfaces in holes or like openingsrequired in catheters (see US. 2,972,779). Any procedure of this typewhich is used must not adversely aiiect the strength, non-toxic or otheressential characteristics of the catheter and should not materiallyincrease the costs of manufacture.

OBJECTS The principal object of this invention is the provision of newforms of catheters of the single use disposable type made fromwaterproof, non-fibrous plastic material which permit the position ofthe distal end portion of the catheter within living tissue into whichthe catheter may be inserted to be determined by X-ray observation.

Further objects include the provision of:

(1) New methods of making plastic catheters which simultaneously createsmooth rounded surface inlet openings in the distal end portion ofcatheters and provides an X-ray observable marking upon the distal endportion of the catheter.

(2) New catheter constructions which enable X-ray observation todetermine where the tip of a catheter is within living tissue into whichthe catheter is inserted and the angle of the tip within the tissue, anaccomplishment which cannot be attained through the use of X-ray linecatheters known heretofore.

(3) New catheter constructions which provide greater X-ray opacitycontrast than has been possible with related X-ray markedmedico-surgical tubes known heretofore.

(4) Catheters having smoothly rounded inlet openings in the distal endportion which are defined by an integral X-ray opaque annulus and whichcan be manufactured and sold at costs competitive with related plasticdisposable catheters available heretofore which do not include suchimproved features.

(5) Such catheters in which tendency of the catheter to bend or buckleat an inlet eye during use is mitigated.

Other objects and further scope of applicability of the presentinvention will become apparent from the detailed description givenhereinafter; it should be understood, however, that the detaileddescription, while indicating preferred embodiments of the invention, isgiven by way of illustration only, since various changes andmodifications within the spirit and scope of the invention will becomeapparent to those skilled in the art from this detailed description. Itshould also be understood the foregoing abstract of the disclosure isfor the purpose of providing a non-legal brief statement to serve as asearching-scanning tool for scientists, engineers and researchers and isnot intended to limit the scope of the invention as disclosed herein noris it intended it should be used in interpreting or in any way limitingthe scope or fair meaning of the appended claims.

SUMMARY OF THE INVENTION These objects are accomplished according to thepresent invention by forming catheters of transparent, non-fibrous,waterproof plastic material, that is non-absorptive to body fluids, witha distal end portion of the catheter having a plastic member fused tothe tube, the member containing X-ray opaque pigment uniformly dispersedtherein in suflicient quantity to permit it to be observed byX-rayswithin living tissue into which the catheter may be inserted.

The objects are further accomplished according to the invention by amethod of making such new plastic catheters with the X-ray observationoutlined portion which comprises:

(a) Forming non-fibrous, transparent tubing of waterproof plasticmaterial by extrusion,

(b) Cutting the tubing into a length required of a catheter,

(c) Forming at least one inlet opening in the distal end portion of saidlength of tubing,

(d) Providing an annulus wafer or like member of plastic materialcontaining X-ray opaque pigment uniformly dispersed therein of desiredconfiguration, and

(e) Fusing said member to said tube by heat and pressure to render themember integral with said tubing and form a smooth surface on the tube.

The determination of the location of a distal end portion of cathetersis most important in endotracheal tubes, suction catheters, stomachtubes, gastro-intestinal catheters, thoracic catheters, abdominal sumpdrains, heart catheters, ureteral catheters, and feeding tubes and thenew structures and methods of the invention are most advantageouslyapplied to such catheters. Actually, the term catheter as used in thisspecification and the accompanying claims is intended to mean anymedicosurgical tube which includes a proximal end, a distal end portionand a longitudinal bore extending therebetween, with the distal endportion having one or more inlet openings therein and which are designedfor insertion into some tissue, organ, cavity, e.g., vascular orarterial branch, or the like in a patient to serve as a channel forremoving fluids from or introducing fluids into the tissue, organ or thelike within the patient. As just stated in connection with the types ofproducts to which the invention is most advantageously applied, thesedevices are sometimes referred to as tubes and other times as catheters.For the sake of brevity and consistency, the term catheter is used as ageneral designation for any medico-surgical devices of this type,,including those having a single lumen or those of a multiple lumen type.It will be further understood by those skilled in the art that thesecatheters may be further combined with syringes, valves, fluid traps orother units in creating assemblies required for the particular medicalor clinical procedure being applied to the patient.

In one preferred embodiment of catheters of the invention, only a singleinlet opening is provided in the distal end portion and this constitutesthe tip or extreme end of the catheter. In another embodiment, thecatheter has one or more internal X-ray opaque inlet openings in thedistal end portion and, preferably, one of such openings defines thedistal tip or distal extreme end of the catheter and another defines themost proximal inlet opening extending through the side wall thereof.Advantageously, the side wall opening is of a measured predeterminedlength from the distal tip and this length is related to the type of thecatheter and its nominal size. As is well known to the medicalprofession, catheter sizes may be designated in terms of actualdiameters of the tube lumen, e.g., 5.5 mm. ID. or in terms of somearbitrary O.D. size designation, e.g., French.

Although the new methods and resulting catheters of the invention may beused with any suitable thermoplastic material known to be useful in themanufacture of medico-surgical tubing, the invention is advantageouslyutilized in the production of catheters by extrusion from plasticizedvinyl chloride polymers.

BRIEF DESCRIPTION OF THE DRAWINGS Further understanding of the structureof the new catheters of the invention and their method of production maybe had by reference to the accompanying drawings in which:

FIG. 1 is a perspective view of a catheter prepared in accordance Withthe invention.

FIG. 2 is an enlarged fragmentary view of the distal end portion of thecatheter of FIG. 1.

FIG. 3 is an end view of the catheter of FIG. 1.

FIG. 4 is a diagrammaticfragmentary view partially in sectionillustrating a stepin the manufacture of the new catheters.

FIG. 5 is a fragmentary side view partially in section illustrating thecompletion of the manufacturing operation as shown in FIG. 4.

FIG. 6 is a perspective, fragmentary view of another form of catheter inaccordance .with the invention.

FIG. 7 is a perspective, fragmentary view of an open end form ofcatheter according to theinvention.

vFIG. 8 is a fragmentary, side view of the catheter distal end portionof FIG. 7. I

FIG. 9 is a perspective, fragmentary view. of a closed end form ofcatheter according to the invention.

FIG. 10 is a fragmentary,.side view of the catheter distal end portionof FIG. 9.

' FIG. 11 is a perspective, fragmentary view of the distal end portionof a catheter haxing X-ray outlined open end, side eye and indicator dotin accordance with the invention.

FIG. 12 is a perspective, fragmentary view of another embodiment ofcatheter similar to FIG. 11, but with an X-ray band indicator instead ofa dot.

FIG. 13 is a perspective fragmentary view of yet another form ofcatheter in accordance with the invention.

FIG. 14 is an exploded, perspective, fragmentary view illustrating astep in the production of the catheter of FIG. 13.

FIG. 15 is a perspective, fragmentary view of a further embodiment of acatheter in accordance with the invention.

FIG. 16 is an exploded, perspective, fragmentary view illustrating astep in the production of the catheter of FIG. 15.

DESCRIPTION OF PREFERRED EMBODIMENTS Referring in detail to the drawing,the catheter 2 constitutes an endotracheal tube having a proximal end 4,a distal end portion 6 and a longitudinal bore 8 extending therebetween.'The catheter 2 is formed of transparent, nonfibrous, waterproof plasticmaterial and in the central body portion 10 designations 12, such as inkembossed markings, are provided to indicate the distance along thecatheter from the inlet tip, e.g., 12, 13.5 and 15 cm. for a 5.5 mm.I.D. size endotracheal tube.

FIG. 2 illustrates in more detail the construction of the distal endportion of the catheter 2 which has a single inlet opening 14, the locusof which is a plane running at an acute angle to the axis of thelongitudinal bore 8 of the catheter. Accordingly, the periphery 16 ofthe opening 14 is elliptical in shape when viewed from the side as inFIG. 2. However, when viewed end on as in FIG. 3, the inlet openingappears circular since it defines the tip or extreme end of the catheterand presents in section the full lumen of the catheter. The periphery.16 of the X-ray opaque plastic section is of limited longitudinal.extent relative to the length of the tube and of varied displacementrelative to the longitudinal axis of the tube.

The periphery 16 of the opening 14 has smoothly rounded edges 18 and theopening is defined by an integral plastic annulus containing X-rayopaque pigment uniformly dispersed therein. 1

In contrast to X-ray marked catheters'known hereto fore, it is possiblewith X-ray tip catheters of this invention to determine the angle-of thetip relative to tissue within which the catheter may be inserted.Further, since the X-ray tip when radiated from the side, such as in theplane of the drawing of FIG. 5, will give a screening to the X-rays bymore than double the thickness of the wall of the catheter. Accordingly,the opacity contrast which can be attained is critically improved ascompared to the single thickness screening which can be obtained withcontinuous line X-ray marking such as known heretofore.

Construction of peripheral outline X-ray openings in catheters accordingto the invention can be obtained by the methods diagrammaticallyillustrated in FIGS. 4 and 5. This is started by provision of a suitablysized tube which can be created in any suitable fashion. Advantageously,a section of plastic tubing 20 is formed of nonfibrous transparentwaterproof plastic material by extrusion. This tubing is then cut into arequired length for a catheter and one or more inlet openings are cut inits distal end portion. In the tubing 20 of FIG. 4, this is done byslicing the end 22 on the tubing 20 at an acute angle to thelongitudinal bore 24 which extends through the tubing. In a separateoperation, a plastic washer or annulus 26 containing X-ray opaquepigment uniformly dispersed therein is created, such as by extrudingtubing of plastic material with the opaque pigment and then slicingwashers, such as the washer 26, from it. This combination is theninserted into a suitably shaped die and while heat is used to soften thetubing end and washer 26, pressure is applied to force the assemblytogether and form an integral unit from the tube 20 and the plasticannulus 26 as shown in FIG. 5. Such heated pressing of the assembly willfuse the annulus to the tube and at the same time create the roundededge 28 on the inlet opening.

As shown in FIG. 6, other forms of catheters in accordance with theinvention may have a plurality of inlet openings in the distal endportion each presenting the X-ray detection feature. Thus, the catheter30 has a square end tip 32 defined by the integral X-ray opaque pigmentcontaining annulus and a second inlet opening 34 extending through theside wall of the tube 30 defined by another integral plastic annulus 36containing uniformly dispersed X-ray opaque powder.

Another form of open end catheter 40 is shown in FIGS. 7 and 8. TheX-ray opaque distal tip 42 is slightly restricted in cross-section ascompared with the lumen of the tube. Most open end catheters are of thisreduced tip area type.

A closed end form of catheter 44 is shown in FIGS. 9 and 10. The X-rayopaque tip 46 is produced by fusing a flat wafer of X-ray opaque plasticto the open end of the tube 38 and at the same time molding the heatsoftened wafer into the rounded shape of the tip 46.

The catheter 50 shown in FIG. 11 comprises an X-ray opaque outlined opentip 52, X-ray eye 54 and X-ray dot 56. The tip 52 and eye 54 are formedby fusing and molding suitably sized X-ray opaque plastic rings to theperiphery of holes in the tube 58. The dot 56 is formed by fusing anX-ray opaque plastic wafer to a hole in the side wall of the tube 58, atthe same time molding the wafer so as to form a smooth butt jointbetween the tube and the wafer.

The formation of the eye 54 as described can provide, in addition to theX-ray outline feature, another advantage, i.e., a stiffening of the tubeWall surrounding the eye. As is well known by users of plasticcatheters, they have a tendency to bend or buckle at the inlet eyes whenbeing inserted in a patient or otherwise handled. This buckling cancause injury to the patient or present other problems to the correctinsertion or use of the catheter. By using an X-ray opaque plasticannulus which is formed of stiffer or more rigid plastic material thanthe tube 58 to which it is fused, the resulting integral X-ray outlinedeye structure 54 exhibits appreciably less tendency to bend or buckle.

The form of catheter 60 seen in FIG. 12 comprises the X-ray tip 62,X-ray eye 64 and X-ray band 66. The band 66 is made of X-ray opaqueplastic material and may be fused into the wall of the tube 68, eitherinside or outside. Alternatively, the band can be butt welded to aseparate tube front portion 70 and main tube portion 68,

6 thereby making a catheter with uniform cross-section in the region ofthe band 66.

FIGS. 13 and 14 illustrate a catheter 72 having an X- ray band 74 at thecatheter tip. Such a structure is useful where a greater X-ray opaquearea is required than with the catheter 40 of FIG. 7. The catheter 72can be made by pushing a tubular X-ray opaque plastic section 76 intothe bore of the tube 78 and welding the section 76 to the tube bysolvent or by heat and pressure.

The form of catheter 80 shown in FIG. 15 comprises X-ray markings 82-88formed from plastic filaments of X-ray material. A catheter of this typemay be made by extrusion of a plastic tube having a main lumen 92 and asmall wall bore 94. A section of X-ray opaque filament 96 is insertedinto the bore 94. The X-ray opaque filament or rod 96 may be fused inthe bore 94 at a de-' sired location by solvent action or by heat.Alternatively, the filament section may be held in position merely by asnug fit between it and the small lumen. After positioning of the X-rayopaque rod or filament, the exposed ends of the lumen 94 may be fused orotherwise sealed to close off the minor bore 94 from subsequent entranceof fluids. In this manner, a variety of X-ray markings may be created,e.g., the tip marking 82, the eye location marking formed by theinterruption between filament portions 84 and 86, and a reference marker88 to designate a given distance along the catheter from the tip 98.

In the use of catheters of the new type as described, special handlingprocedures are not required. Thus, the new catheters can be sterilized,handled, packaged, manipulated or stored under the same conditions andhandling procedures familiar to physicians, surgeons and other personnelaccustomed to working with the disposable plastic typecatheters.Moreover, the catheters can be formed to include bubbles, taperedsections, O-ring additions or any other auxiliary elements with whichcatheters are now produced or may be required to be formed in thefuture. Similarly, the catheters may be made to have substantiallyuniform wall thickness throughout their length or, where specialapplication or professional preference dictates, tapered portions orwall sections of varied thickness may be provided in the catheters byair blowing, vacuum drawing or other techniques known to the plasticsart.

The embodiments of the invention in which an exclusive property or rightis claimed are defined as follows:

1. A catheter formed of transparent, non-fibrous, waterproof plasticmaterial that is non-absorptive to body fluids, having a proximal end, adistal end portion and at least one longitudinal bore extendingtherebetween, said distal end portion comprising at least one inletopening, the periphery of said opening being smoothly rounded and beingdefined by an integral plastic annulus containing X-ray opaque pigmentuniformly dispersed therein in sufficient quantity to permit theposition of the distal end of the catheter within living tissue intowhich the catheter may be inserted to be determined by X-rayobservation.

2. A catheter as claimed in claim 1 having a single inlet opening in thedistal end portion, said opening defining the extreme end and presentingthe full lumen of the catheter.

3'. A catheter as claimed in claim 2 wherein the locus of said openingis a plane which is at an acute angle to the axis of the longitudinalbore of the catheter, said opening being elliptical in shape.

4. A medico-surgical tube as claimed in claim 1 wherein said annulus ismade of plastic material which is more rigid than the plastic materialof which said catheter is formed.

5. A catheter as claimed in claim 1 wherein said inlet opening extendsthrough the side wall of said distal end portion.

6. A catheter as claimed in claim 1 wherein there are a plurality ofsaid integral X-ray opaque inlet openings in the distal end portion ofthe catheter, one of said openings defining the tip of the catheter andanother defining the most proximal opening extending through the sidewall thereof.

7. A catheter as claimed in claim 5 wherein the distance between saiddistal ti opening and said side wall opening is of measured,predetermined length related to the type and size of the catheter.

8. A catheter formed of transparent non-fibrous, waterproof plasticmaterial having a proximal end, a major longitudinal bore, a minorlongitudinal bore, and a distal end portion having a plurality of inletopenings therein, one of said openings defining the tip of the catheterand a second opening extending through the side wall of said distal endportion, said minor bore being of a diameter less than the wallthickness of the catheter and positioned within the Wall of the catheterwith the catheter presenting substantially smooth inner and outer walls,said second opening interrupting said minor bore in said distal endportion, a section of X-ray opaque filament or rod being fixed in saidminor bore on each side of said second opening marking the distal andproximal extremities of said second opening, said minor bore beingclosed at the ends against entrance of fluids.

9. A catheter of claim '8 wherein a section of X-ray opaque filament orrod extends to the tip of the catheter, the periphery of said opening inthe catheter tip is smoothly rounded and the distal extremity of sectionthat extends to said tip is included in a portion of said periphery.

References Cited

